People who feel lonely are twice as likely to develop type 2 diabetes, according to a new Norwegian study that analyzed data collected from more than 24,000 people over more than 20 years.
Diabetes has become one of the top 10 causes of death worldwide, according to the World Health Organization (WHO), with the number of people diagnosed with the disease increasing significantly over the past 20 years. The WHO reported a 70% increase since 2000 and said the disease was also behind the biggest rise in male deaths among the top 10 global causes of health-related death.
The latest peer-reviewed study, published in Diabetologia, the journal of the European Association for the Study of Diabetes, builds on recent research that suggests feelings of loneliness and psychological stress may be a risk factor for type 2 diabetes. , is one of the first population-based studies to analyze this association.
While researchers are still trying to fully understand the connection between stress and type 2 diabetes, it is thought that high levels of cortisol, a stress hormone, can result in temporary insulin resistance. This, in turn, can affect how the brain regulates eating behaviors, such as craving more carbs, which can raise blood sugar levels.
Researchers at the Western Norway University of Applied Sciences examined this association and whether it could also be a result of depression and insomnia, as both have been linked to loneliness and diabetes.
Data collected from the HUNT study, a collaboration between the HUNT Research Center at the Norwegian University of Science and Technology and several Norwegian health organizations and authorities, were used by the researchers for analysis. The HUNT study collected information from self-reported questionnaires, medical tests and blood samples in four population surveys conducted between 1984 and 2019 with more than 230,000 people. The researchers focused on data collected from 24,024 individuals between 1995 and 1997 as a baseline and whether these individuals eventually developed type 2 diabetes over more than two decades.
The scientists found that those who expressed feelings of loneliness at baseline from 1995 to 1997 “were strongly associated with a higher risk of type 2 diabetes measured 20 years later,” according to the article.
The study found that 4.9% of people in the group, or 1,179, developed Type 2 diabetes. Nearly 13% of study participants said they experienced feelings of varying degrees of loneliness. Results also showed that men were more likely to develop type 2 diabetes at 59.3% compared to 44% of women, and were older at 47.9 years of age. Those with type 2 diabetes were also more likely to be married, at 73.1 percent compared to 67.5 percent, and less educated, at 34.8 percent compared to 23.3 percent.
“We also found a statistically significant but weak mediating effect of sleep maintenance insomnia. However, the results did not support our hypotheses that the association between loneliness and type 2 diabetes is mediated by initial insomnia, terminal insomnia, or depressive symptoms,” the authors wrote.
“After adjusting for age, gender, and educational level, we found that participants who answered ‘a lot’ to the question about feeling lonely were twice as likely to develop type 2 diabetes 20 years later than those who did not feel lonely.”
The latest research supports the findings of two recent prospective studies that examined loneliness and type 2 diabetes risk and found that loneliness is a “significant predictor” of the disease after adjusting for several factors, such as gender, age, education, alcohol consumption, physical activity, and body mass index.
The researchers expressed some caution in interpreting their results, although they were in line with previous studies. Some follow-up data from the last population survey conducted between 2017 and 2019 were incomplete, and a large number of participants from the most recent survey were also excluded due to lack of information about blood test results. The authors noted that both factors were potential sources of bias and could affect the results.
Furthermore, type 2 diabetes was based on diagnostic tests for hemoglobin A1c that measure the amount of sugar in the blood linked to hemoglobin, meaning that those taking medications to regulate diabetes may have been classified as not having the disease.
Finally, many of the variables were based on self-reported questionnaires, raising the possibility that some participants may have given inaccurate responses.
While not part of the study, the authors noted that friends and family can have a favorable and positive influence on an individual’s health, including diet, physical activity and general stress, and those who are lonely may be more vulnerable to habits and behaviors that put them at greater risk of developing diabetes.
“It is important for healthcare professionals to be open to dialogue about an individual’s concerns during clinical consultations, including with regard to loneliness and social interaction,” the authors concluded.